The residual background genome from a donor within an improved line selected by marker‐assisted selection: impact on phenotype and combining ability

Abstract

AbstractA successful marker‐assisted selection (MAS)‐derived line should express new characteristics derived from the donor, and have a small number of donor chromosomal fragments. Different selection strategies can result in a different proportion of donor residual background within the improved line. The effects of the residual background on phenotype and combining ability mostly remain unknown. In this study, waxy (wx) and a restorer gene (Rf3) of S‐type cytoplasm sterility were selected as a model for MAS breeding by three strategies, to develop MAS‐derived lines with a different level of residual background. Three MAS‐derived lines were successfully developed by introgression of the target gene. Furthermore, the genetic background, agriculturally important traits and combining ability of the three MAS‐derived lines were assayed. The results suggested that the three MAS‐derived lines retained 4–18% of the chromosomal fragment of the donor, respectively, and the residual background impacted on the phenotype of important traits and combining ability of MAS‐derived lines. We also showed that whole genome background screening each backcross generation can accelerate recovery of the recurrent parent genome, phenotype and combining ability.